In recent years, 3D cultivations of moving cells such as cardiac myocytes have become popular (see, for example, Non-patent Document 1). Unlike 2D cultivations in which a cell group 2-dimensionally forms a single layer, the 3D cultivations can obtain cell groups connected 3-dimensionally and obtain cell groups in a state close to an actual intravital state.
It is required to realize, in observing such 3D-cultivated cells as the observation object, a 3-dimensional recognition (3D recognition) of the state of the observation object. As a method of realizing the 3D recognition, there is a method that uses a scan-type microscope system such as a scan-type two-photon excitation laser microscope and confocal laser microscope. In the scan-type microscope system, the 3D recognition of the observation object is realized by 2-dimensionally scanning it while changing a laser focal position in an optical-axis direction (see, for example, Patent Document 1).
The 3D recognition is also realized by carrying out image processing on an image captured with a microscope. For example, a 3D image of an observation object can be obtained by using an autofocus function of detecting a focal plane or a function of generating an omnifocal image.
Patent Document 1: Japanese Patent Application Laid-open No. 2005-128086
Non-patent Document 1: Three-dimensional cell culture: the missing link in drug discovery., Drug Discov Today. 2013 March; 18(5-6):240-9.